Some automobiles have need of a door that may swing open greater than 90°. A specific example is a truck with an extended cab. Rear doors for an extended cab are generally appreciably narrower than front doors and as such, may need to be swung open close to 180° in order to facilitate loading bulky items and people into the extended area of the cab. Hinges that allow for close to 180° of movement are generally not constructed to rigidly restrain movement of the door slightly past the fully open position. In the case of a rear door on a truck, movement of the door past a 180° position may cause contact of the door against the bed of the truck. Contact between these structures usually affects damage to at least one and probably both of them.
It is also preferable for the rear door to have an intermediate position between the fully open and fully closed positions to prevent the need to move the door the entire distance of travel to the fully open position in order to enter the vehicle and then to again move the door the entire distance of travel in order to close the door. Additionally, once a passenger has entered and is situated within the vehicle, it is generally difficult for that passenger to then move the door toward and into the closed position from the fully open position, since this operation requires the passenger to reach outwardly and rearwardly of the door opening and then affect an outwardly directed closing force on the door. Furthermore, passengers may utilize the rear door, when in the intermediate position, as a handle or support to facilitate entering and exiting the vehicle, especially when the vehicle is relatively high from the ground.
To solve this problem, previous designs of hinges for this type of door have called for an intermediate position, which prevents the door from moving therepast toward and/or into the fully open position. These hinges however have had a primary disadvantage. Usually only one hinge per door was provided with stopping structure to provide the intermediate position so that the user need not manipulate two latch mechanisms (as would be present if two hinges each having a stopping structure were used) to release the door from the intermediate position. However, since only one of the hinges is provided with stopping structure, upon rapid opening of the door to the intermediate position, or applying a force on the door once in the intermediate position (such as a passenger leaning or steadying themselves on the door, or a wind gust), the door may undergo flexural loading about the hinge with the stopping structure. This may cause warpage of the door and of one or both of the hinges. Once the door and/or hinge(s) are warped, proper operation and/or sealing of the door (against the vehicle body when closed) is seldom achievable.
A previous type of hinge, disclosed in U.S. Pat. No. 4,744,127, includes a door mounting bracket, a body mounting bracket, and an intermediate member pivotally connected to each bracket at respective ends thereof. The hinge of the '127 patent provides to a door mounted thereto 180° of pivotal movement sequentially about two axes. However, the hinge of the '127 patent fails to provide an intermediate position of the door wherein the door is prevented from further pivotal movement past the intermediate position towards the fully open position. As disclosed, the hinge of the '127 patent provides a spring bias of the door in the fully open position. An extension spring is connected between the intermediate member and the door mounting bracket. The spring is arranged to go into an over-center orientation upon achieving the fully open position relative to the pivot axis provided between the door mounting bracket and the intermediate member to thereby bias the intermediate member into the fully open position. As such, the door is predisposed to move into the fully open position and requires, in order to close the door, the passenger to apply sufficient force on the door to overcome the spring bias retaining the door in the open position. Applying sufficient force to overcome this spring bias on the door may prove to be difficult, especially from a position within the vehicle, as described above.
The present invention avoids these limitations by providing a door hinge system for supporting a vehicle door on a vehicle body so that the vehicle door is movable to a fully closed position, a fully opened position, and an intermediate position between the fully open and fully closed positions. The hinge system of the present invention comprises a pair of hinge assemblies. Each of the hinge assemblies comprises a body mounting structure configured to be mounted to the vehicle body, a door mounting structure configured to be mounted to the vehicle door, and a dual pivot swing arm. The swing arms are respectively pivotally connected to the body mounting structures for relative pivotal movement about a first axis and are also respectively pivotally connected to the door mounting structures for relative pivotal movement about a second axis. Each of the hinge assemblies includes a swing arm latch, which is movable between a latched position and a released position. The latches are normally in the latched positions thereof. At least one of the hinge assemblies provide a stop surface, which is positioned such that, when the door and body mounting structures are mounted to the vehicle door and body, respectively, movement of the vehicle door towards the fully open position is limited to pivotal movement about one of the first and second axes by the latches being in the latched positions thereof. The vehicle door then is stopped at the intermediate position by the stop surface so that movement of the latches to the released positions thereof and subsequent pivotal movement of the vehicle door about the other of the first and second axes is required to enable the door to be moved from the intermediate position to the fully open position. The hinge system also includes a single manually operable release member operatively connected to each of the latches. The release member is manually movable to affect movement of each of the latches from the latched positions to the released positions thereof.